Django向后外键查询不工作

Question

嗨，我正在django上的聊天应用程序与django频道工作，我试图在这里查询用户的所有第一个消息，当我做

user.message_set.all()

it is throw

AttributeError at /
'User' object has no attribute 'message_set'

完整回溯:

Traceback (most recent call last):
File "/home/__neeraj__/.local/lib/python3.9/site-packages/django/core/handlers/exception.py", line 47, in inner
response = get_response(request)
File "/home/__neeraj__/.local/lib/python3.9/site-packages/django/core/handlers/base.py", line 181, in _get_response
response = wrapped_callback(request, *callback_args, **callback_kwargs)
File "/home/__neeraj__/Documents/chat/home/views.py", line 10, in index
print(i.messages_set.all())
AttributeError: 'User' object has no attribute 'message_set'

我models.py

class Message(models.Model):
sender = models.ForeignKey(User, on_delete=models.CASCADE, related_name="sender")
receiver = models.ForeignKey(
User, on_delete=models.CASCADE, related_name="receiver"
)
text = models.CharField(max_length=2000)
created_on = models.DateTimeField(auto_now=True)

my view:

def index(request):
users = User.objects.all()
context = {"users": users}
for user in users:
print(user.message_set.all())
return render(request, "index.html", context=context)

这是因为我在消息表上有用户模型的双外键引用吗?

Answer 1

您指定的related_name非常不正确。(根据您当前的配置，您可以执行user.receiver.all()来获取接收到的消息，但这对于阅读器来说意义不大。)

你需要像

sender = models.ForeignKey(User, on_delete=models.CASCADE, related_name="messages_sent")
receiver = models.ForeignKey(User, on_delete=models.CASCADE, related_name="messages_received")

之后可以使用user.messages_received.all()和user.messages_sent.all()。